Yes. It would be transformative in ways both readily imagined and yet to be imagined. It isn't entirely sunshine and rainbows, as one must take care to remain

Yes. It would be transformative in ways both readily imagined and yet to be imagined. It isn't entirely sunshine and rainbows, as one must take care to remain below the material's critical field for it to remain superconducting, but beyond that, much of what a thoughtful freshman-physics student might dream up is likely to be possible. Such a discovery would revolutionize a lot more than power-transmission. One of the first places it would have impact is in MRI, where magnet-cooling is a major expense. The ripple effects of such a discovery would be very fast, just as high-Tc was in 1986/1987. Even if the material is a strange one, everyone would race to find a way to use it. Edit: First applications might probably appear in situations that can use small quantities of the material -- building great filters in circuits/ICs would require minimal material-handling R&D.